1. Field of the Invention
The present invention relates generally to chemical formulations used in semiconductor wafer fabrication and particularly to chemical formulations that are utilized to remove residue from wafers following a resist plasma ashing step.
2. Description of the Prior Art
The prior art teaches the utilization of various chemical formulations to remove residue and clean wafers following a resist ashing step. Some of these prior art chemical formulations include akaline compositions containing amines and/or tetraalkyl ammonium hydroxides, water and/or other solvents, and chelating agents. Still other formulations are based on acidic to neutral solutions containing ammonium fluoride. The various prior art formulations have drawbacks which include unwanted removal of metal or insulator layers and the corrosion of desirable metal layers, particularly aluminum and aluminum-copper alloys and titanium nitride features. There is therefore a need for chemical formulations which effectively remove residue following a resist ashing step which do not attack and potentially degrade delicate structures which are meant to remain on a wafer.